"I'm a bit nervous more than confident," McGarvey-Black said.
McGarvey-Black admitted confidence was his biggest weakness, but he said he was prepared to give all he could in his bid.
He said he had enjoyed every part of the training so far - from just being around the best players in the country - many of whom he looked up to, getting the feel of the atmosphere, while also gaining as much knowledge as possible to move forward in his career.
"The boys are great," he said.
"For me it's about gaining more knowledge, learning off the coaches and keeping on improving every day."
He said he had been warned sevens on an international stage was stronger, faster and smarter than anything he would have played before so to be prepared for it if given the chance to face off with the world's best players.
"I like a challenge, I'm up for anything, I hate losing but I can take one.
"I just hate letting people down, that's probably my biggest fear."
McGarvey-Black comes from a family heavily involved in touch rugby so progression through 15-a-side rugby union and then on to the sevens format has been a natural one.
Growing up in Ruatoki, McGarvey-Black started playing JAB rugby from the age of about 8 and said working on the family farm running around herding cows became "sort of like our training" for his sports career.
He moved to Rotorua to spend his high school years at Rotorua Boys' High School, finishing in 2015 and that's where he first got a taste of sevens.
Currently based in Ruatoki, McGarvey-Black is planning to move to Tauranga by the end of this month.
All Blacks Sevens 2018 schedule:
January 26-28: Sydney
February 3-4: Hamilton
March 2-4: Las Vegas
March 10-11: Vancouver
April 6-8: Hong Kong
April 13-15: Gold Coast
April 28-29: Singapore
June 2-3: London
June 8-10: Paris
July 20-22: San Francisco
Black Ferns Sevens 2018 schedule:
January 26-28: Sydney
April 13-15: Gold Coast
April 22: Kitakyushu
May 12-13: Langford
June 8-10: Paris
July 20-22: San Francisco